document.write( "Question 112724: this is the problem
\n" ); document.write( "If an object is propelled upward from the ground level with an initial velocity of 42.9 ft. per sec, it's height h in feet t seconds later is given by the equation h=-16t^2+42.9t. After how many seconds does the object hit the ground? \n" ); document.write( "

Algebra.Com's Answer #82354 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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f an object is propelled upward from the ground level with an initial velocity of 42.9 ft. per sec, it's height h in feet t seconds later is given by the equation h=-16t^2+42.9t. After how many seconds does the object hit the ground?
\n" ); document.write( ":
\n" ); document.write( "You know that when the object hits the ground, h = 0
\n" ); document.write( "Therefore just put the equation = to 0 and solve for t:
\n" ); document.write( ":
\n" ); document.write( "-16t^2 + 42.9t = 0
\n" ); document.write( "Factor out -t (changes the signs)
\n" ); document.write( "-t(16t - 42.9) = 0
\n" ); document.write( "Two solutions
\n" ); document.write( "t = 0; when the object is propelled upward
\n" ); document.write( "and
\n" ); document.write( "16t = 42.9
\n" ); document.write( "t = $\"42.9%2F16\"$
\n" ); document.write( "t = 2.68 seconds when the object strikes the ground \n" ); document.write( "

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